Many halagonated compounds, notably chlorinated compounds and in particular polychlorinated aromatic or alicyclic compounds are known to be useful in various fields of industry.
They include, for example, pentachlorophenol (PCP) having herbicidal and fungicidal activities, hexachlorocyclohexane (BHC) having insecticidal activity and polychlorinated biphenyl (PCB) used for the heat medium.
There are many methods for treating them after use thereof.
For example, in the case of PCB charged in transformers, it may be simply buried in the soil. This, however, can cause pollution as it may contaminate the water system under the ground. Another method is degrading halogenated organic compounds by combusting them. However, halogenated organic compounds are generally resistant to the heat degradation, and hence, considerably high temperature such as 1,300.degree. C. or higher is required for the complete degradation of these compounds, and this makes the method inefficient. Moreover, heating of halogenated organic compounds can cause conversions of such compounds to highly toxic substances, such as polychloropolybenzodioxine (PCDD) or polychlorodibenzofuran (PCDF), which may be discharged to the environment.
Such highly toxic substances not only are generated as a result of heat conversion but are present as impurities of halogenated organic compounds in the bulk form such as PCP or 2,4,5-trichlorophenoxyacetic acid (2,4,5-T).
It is, therefore, very important to process halogenated organic compounds and/or highly toxic polyhalogenated substances efficiently without causing pollution of the environment.